Light projecting device



Oct.'25, 1938. w. L. ENFIELD LIGHTYPROJECTING DEVICE Filed March 26, 1937 3 Sheets-Sheet 1 Inventob:

w y a e n m E r L. m 2 a A. w y b Oct. 25, 1938. w. ENFIELD LIGHT PROJECTING DEVICE Filed March 26, 1937 3 Sheets-Sheet 2 Inventor:

d l e F n n E r L w X Mf WI H y b Aug. 28, 1951 E. DOUGHERTY TORQUE CONVERTER 3 Sheets-Sheet 3 Filed July 8, 1949 INVENTOR. LEM EL E DO GHER Y WWQ ATTORNEY In lamps of this type, a filament or-other con- Patented Oct." 25, 1938 UNITED STATES 2.134.551 uen'r momc'rmo nnvrcn William L. Enfield, Shaker Heights, Ohio, assignor to General Electric Company, a corporation of New York Application March 26,- 1937, Serial No. 133,220

2 Claims.

My invention relates to light projecting devices generally and more particularly to such devices suitable for use where a concentrated beam of light is desired at a given distance from the device, for example, in moving picture studios and theaters, although it is readily adapted to omce and factory lighting and other types of light projection. 7

My projection device advantageously employs reflector lamp units of the type described and claimed in co-pending application Serial No. 68,713, filed March 13, 1936, by Daniel K. Wright.

centrated light source is precisely positioned at the focal point of the accurately formed glass,

parabolic reflector portion of the lamp, thereby resulting in the projection of a powerful and efiicient beam of light.

One object of my invention is the provision of a light and compact light projection device of limited depth, consisting of a plurality of lamp units, preferably of the type disclosed in the aforementioned co-pending application, mounted in a holder in a plane common to all of said lamp units.

Another object is the provision of a light projection device consisting of a fixed central reflector lamp surrounded by a ring of reflector lamps, some or all of which may be adjustable.

Still another object of my invention is the provision of a light projection device comprising a plurality of individual reflector lamps adapted to project a beam of light which may be concentrated or focused at substantially any given distance from said device, the cross-sectional size of the composite beam at such point of concentration being no greater than that of one of the constitutent beams.

A further object of my invention is the provision of means for focusing orconcentrating the beams of light projected by the various reflector lamps mounted within my projection device at any given distance from the same.

A still further object is the provision of pivotal mountings for the adjustable lamps of my projection device whereby said lamps are capable of pivotal movement in a plane radial to the central lamp of said device.

Other objects and advantages of my invention will be apparent from-the following detailed description of a species'thereof and from the accompanying drawings, in which:

Fig. 1 is a front elevation of a projection device comprising my invention, showing the arrangementof the various individual reflector lamp units included therein; Fig. 2 is a side elevation of my projection device, further illustrating diagrammatically the manner in which the beams of light from the various individual adjustable lamp units may be concentrated or focused at any given distance from the projection device; Fig. 3 is a vertical sectional view taken on the line -33 of Fig. 1; Fig. 4 is a horizontal sectional view taken on the line 4-4 of Fig. l; and Fig. 5 is a rear elevation of my projection device with a portion ,of the rear cover plate broken away.

Referring to the drawings, my projection device comprises a central reflector lamp unit l0 surrounded by a group of adjustable reflector lamp units ll, all mounted in a holder l2. The holder may be made of Dural metal or any othe suitable light weight material. The reflector lamps are of the type disclosed in the previously mentioned co-pending application Serial No.

68,713, each comprising a lens I3 sealed at the 20 periphery thereof, at It, to a preformed reflector portion l5. This reflector portion is made of pressed glass, the interior surface It of which is preferably of paraboloidal shape and covered with a coating ll of aluminum, for example, constituting a reflecting surface. A concentrated light source, comprising a bar filament l8 disposed transversely of the reflector axis, is mounted within the lamp by lead wires l9, terminal prong members 20,- and metal cups 2|, and is accurately positioned at the focal point of the reflector surface ll. The greater accuracy with which the pressed glass paraboloidal interior surface Hi can be formed over the conventional stamped metal reflectors, together with the extremely accurate disposition of the concentrated light source l8 at I the focal point of the reflector surfaee l1, results in the projection of a powerful and eillcient beam of light.

The holder i2 is drum shaped and comprises a cylindrical body portion 22, a front cover 23, and a rear cover 24. The front cover 23 is provided with a plurality of openings 25 adapted to receive the various reflector lamps Ill, II. A peripheral flange 26 formed on said front cover is adapted to telescopically engage with the cylindrical body portion 22 to thereby secure said parts together. The body portion 22 is formed adjacent the rear extremity thereof with spider-like reinforcing means comprising a hub 21 and a plurality of so spokes or arms 28 connecting said hub with a circumferential strengthening flange 29 extending inwardly from the inner cylindrical surface of the body portion. The rear cover 24 is formed with a peripheral flange 30, similar to the flange 55 to the body portion by a pair of wing nuts 8i, 3|, which are adapted to be threadedon a pairof bolts 32, 82 fastened to certain of the arms ll.

Whereas the central lamp II is flxedly mounted in the holder II with its reflector axis substantially parallel to the axis of said holder, the surrounding ring of lamps II are adjustably mounted in said holder. Refer-ring to Figs. 3 and 4, each of the adjustable lamps I I is inserted in a socket ll pivotally mounted on the rear of the front cover 23 of the holder l2. Each socket 33 comprises an insulating member 84 preferably formed of hard rubber or the like and provided with a pair of hollow metallic cylinders or contact members 3|, 8! adapted to recdve, and convey current to, the terminal members ll of the reflector lamp II. The contact members in each socket 33 are connected to the electrical circuit by means of the bolts ll, 36 and connecting wires, it being understood that all of the sockets in the projection unit are connected together to constitute one electrical circuit. A toggle or other type of switch I! may be inserted in the circuit to energize or de-energize the same. The socket contact members 35 are adapted to mount the adjustable lamp II in such a position that the reflector axis thereof will lie in a plane x-x common to such axis and to the axis of the central reflector lamp It. The socket 33 is pivotally mounted at the rear of the front cover 23 of the holder by means of a pair of arms 38, 38 which are fastened to the insulating member I by screws 39 and pivoted on the pins l0, 40 located adjacent the rear surface of the front cover. These pins 40. 40 extend from supporting brackets 4|, 4| rigidly secured to the rear surface of the front cover 23.

As is evident from Figs. 3, 4 and 5, the bar fllament is and terminal members 20, 20 of the lamp ll, together with the socket contact members 35, 35 and pins l0, 40, all lie in a common plane Y-Y (Fig. 5), which plane is perpendicular to the radial plane X--X common to the axes of the central reflector lamp ill and the adjustable reflector lamp ll. Thus, rotation of the socket 33 on the pins 4|, ill will cause the reflector axis of the adjustable lamp II to assume various tilted positions within the radial plane x--x.

While I have described the pivotal mounting of only one adjustable lamp II, it should be un-- derstood that each of the other adjustable lamps II is provided with a similar mounting and is adapted to be tilted or rotated in a similar manner.

Various modifications of the pivotal mounting described above may be employed in place thereof. For instance, the mounting may consist of a pivotally mounted element or elements adapted to engage the periphery of the reflector lamp II and support the same at such point, instead of engaging and supporting such lamp at the terminal members.

The rotatable sockets I: may be either separately or individually controlled, or they may be simultaneously controlled, as is desired. In the accompanying drawings, I have illustrated one type of means for simultaneously controlling rmtative movement of all the adjustable lamps l I.

Referring to Figs. 4 and 5. the insulating member 34 of each socket I8 is provided with a centrally located opening 42 adapted to plwtally receiveaflngeruextendingfrommeendofa 26 on the front cover, for telescopic engagement 7 a with the rear extremity of the cylindrical'body l portion 22. 'lhe rcar cover is securely fastened cover 24, is adapted to operate the control lever It will be observed from Fig. 5 that the point of pivotal connection 45 of the control arm 44 and control lever 48 is removed some distance from the center of the control lever shaft 41, and also from the radial plane x-x. Accordingly, rotation of the control lever it will cause the control arm 44 to rotate the socket a about the pins 4|, 4| either radially inward or outward, depending, of course, upon the direction of rotation of the control lever. Thus, in Fig. 5, clockwise rotation of the control lever it causes the socket II to be rotated radially inward, while counterclockwise rotation of said control lever causes the socket to be rotated radially outward. From Fig. 3, it will be understood that outward rotation of the socket 33 about pins 4|, 4| causes the reflector axis of the lamp II to be tilted or directed inwardly towards the reflector axis of the central lamp il, while inward rotation of the socket :1 causes the reflector axis of lamp ii to be directed outwardly or away from the reflector axis of the central lamp.

Each lamp II is connected to the control lever 46 by a control arm 44 similar to the one described above. By means of the screw and slot adjustment device ll provided in each control arm 44, the position of the various lamps II can be so adjusted that for any one setting of the control lever l, the reflector axes of all the lamps I I will be directed the same amount inwardly towards or outwardly away from the reflector axis of the central lamp ll. Thus, referring to Fig. 2, the beams of light projected by the various lamps II can be quickly and simultaneously concentrated at any distance d from the projection device. To concentrate or focus the composite beam on an object comparatively near said projection unit, it is only necessary to rotate the control lever 46 counterclockwise the required amount. Likewise, to focus the beam on an object fairly distant from said projection device, the control lever is rotated clockwise the required amount.

In Fig.2,thebeamof lightA projected bythe central lamp I0, and the beams B projected by the adjustable lamps II, are shown focused or concentrated at the distance d from the projection unit. It is quite obvious from this illustration that the cross-sectional area or size of the composite-bonnet the distance d is limited in degree of concentration only by the cross-sectional area or size of one of the constituent beams A or B at such distance at.

If, in addition to a concentrated beam of light, a certain amount of asymmetrical illumination is desired, the same may be provided in a number of ways. 'lhus, where the various adjustable lamps are separately or individually controlled,

such asymmetrical illumination may be obtained by simplypositioning one or more of said adjustablelampsoutoffocuswiththeothemwhile in the case of simultaneously controlled lamps itmaybe'readilyobtainedbyadjustingthe lengthoftheconnectingarms ofoneormore of the'adjusteble lamps the required amount.

- that obtainable from a single lamp of .substan-- given distance in front 01' the same.

through the medium of the adjustment devices 5| provided therefor. Alternatively, such asymmetrical illumination may be secured by providing one or more of the lamps with either asymmetrical lenses cr reflectors, or by altering the pivotal mounting of one or more of the adjustable lamps.

If desired, a plurality of my projection devices may be grouped together in the same manner as the individual lamps Ill and I l are grouped in one of my devices, and the same provided with similar control means for projecting and concen-' trating astiil more powerful beam of light which, however, will still be limited in degree of concentration only by the cross-sectional size of one of the constituent beams A or 13. Thus a beam of light of extremely high intensity can be projected onto the object desired to be illuminated. Obviously, the process or grouping a plurality of my projection devices together may be theoretically continued indefinitely while still maintaining the same cross-sectional size of the composite beam at'the point of concentration as that of one of the constituent beams A or B.

From the foregoing description, it will be apparent that I have provided a projection device which is simple in construction and positive in operation, whereby a powerful beam 01' light may be focused or concentrated at substantially any Said beam, at the point of focus, will be concentrated into an area appreciably smaller than that possible with a lamp comprising a single reflector of approximately the same diameter as that of my projection device. In other words: I am able to obtain with my construction of lamp a concentrated beam of considerably higher intensity than tially equivalent size. Furthermore, the use of a plurality of reflector lamps of the type shown in the drawings, having a limited depth, has enabled me to construct a projection device which is light inweight and compact in size, thereby iacilitating transportation of the same.

What I claim as new and desire to secure by Letters Patent of the United States is:

1. A light projecting device comprising a support member, a plurality of annularly arranged holders for supporting light-concentrating lamp units, said holders being pivotally mounted in said support member for rotation in radial planes passing through the axis about which said holders are arranged to permit onvergence of the beams from the lamp units, t a desired distance ahead 01' the device, and means for pivoting said holders comprising a control lever pivotally mounted at one end on the said axis of the holders, and control arms pivotally connecting said holders with said end of said lever, the pivotal connections of said arms to said lever being at points concentrically disposed about the said axis whereby movement of the opposite end of said control lever causes said lamp holders to be simultaneously pivoted to permit convergence of the beams from the lamps.

2. A light projecting device comprising a support member, a plurality of annularly arranged holders for supporting light-concentrating lamp units, said holders being pivotally mounted in said support member for rotation in radial planes passing through the axis about which said holders are arranged to permit convergence of the beams from the lamp units at a desired distance ahead of the device, and means for pivoting said holders comprising a control lever pivotally mounted at one end on the said axis of the holders, and control arms pivotally connecting said holders with said end of said lever, each of said arms being longitudinally extensible to permit variation in the original aiming of said lamp units the pivotal connections of said arms to said lever being at points concentrically disposed about the said axis whereby movement of the opposite end of said control lever causes said lamp holders to be simultaneously pivoted to permit convergence of the beams from the lamps.

WILLIAMLENFIELD. 

